powerpc/32: Enable POWER_RESET in pmac32_defconfig

Enable POWER_RESET, and drop ADB_CUDA as it will now be selected.

Suggested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Yuan Tan <tanyuan@tinylab.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/73716a14e9a24bcea4ca6c454aae308c419933c6.1694685860.git.tanyuan@tinylab.org